Cycler



June l2, 1951 s, w, NlCKELLs CYCLER Filed Feb. 2, 1948 nuentor 5TH/utfWN/ckfu Patented June 12, 1951 UNITED STATES PATENT OFFICE CYCLERDelaware Application February 2, 1948, Serial No. 5,795

'4 Claims. (Cl. 201-63) This invention relates to an electrical controldevice or cycler for periodically operating a power device. Moreparticularly, the invention relates to a cycler suitable forperiodically unbalancing a balanced control system which operates fuelfeeding means in heating apparatus.

It has been found in the heating of homes and other establishments, thatit is highly desirable to more or less continuously supply heat to roomsin which it is desirable to maintain a uniform temperature. In order toobtain this substantially constant supply of heat to a room or rooms ina house, at a temperature which is just suicient to maintain the desiredroom temperature, it is necessary to supply fuel to the furnace at theproper rate.

In fuel feeding apparatus wherein the fuel feeding means eitheroperatesv at a fixed fuel feeding rate or not at all, it is necessary toprovide a control means which periodically turns the fuel feeding meanson and off for as long periods of time and as often as is necessary tomaintain the necessary rate of fuel flow.

It is in a Wheatstone bridge type of control circuit for an on-offfuelfeeding means that the present invention is particularly suited. Insuch a system the cycler would be put in series -with an outdoortemperature compensator in one input leg of the bridge, while one ormore resistance-type of room thermostat would be positioned in the otherinput leg of the bridge circuit. In order for the system to operateuniformly over widely varying temperature ranges, it is apparent thatthe cycler unit must be rugged, sensitive and adjustable to variableconditions, and should operate in la. uniform manner.

Accordingly, it is one of the objects of this invention to provide acycler control device having means for adjusting the control elementsthereof.

Another object of the invention is to provide a cycler which is ofsturdy yet inexpensive construction.

Another object of the invention is to provide a cycler Iwhich is soshielded that it assures uniform operation thereof.

A further object of the invention is to provide a cycler which isreadily connected to and removed from the control apparatus of which itforms a part.

A still further object of the invention is yto provide a cycler whichembodies lall of the above mentioned features in a compact and highlyeflicient control device.

Additional objects of the invention will become apparent upon readingthe following detailed de- Figure 2 is a side view of the controllerwith the housing shown in cross-section; and

Figure 3 is a schematic illustration of a control circuit with thecycler therein.

The cycler comprises a body portion II made of a suitable insulatingmaterial, such as a molded thermosetting plastic. The body has a baseportion I2, in the peripheral edge of which is formed an annularV-shaped groove I3, and a spacer boss I2a forfrninimizing conduction ofheat from said body. The body also has a, bobbin portion formed with aplurality of axially spaced, annular grooves I4, longitudinallyextending grooves I5 and an end portion I6. The end portion has arecessed portion I'I, extensions of grooves I5, centering lugs I8 and aspacing lug I9. The annular grooves are adapted to be selectively usedto hold a coil of heater wire and/or a coil of temperature sensitivewire.

A coil of wire 20, made of metal suitable for use as an electricalheater, such as Manganin wire (84% Cu, 12% Mn and 4% Ni), is selectivelypositioned in one of the grooves I4 with the ends of the wire passinglongitudinally through the grooves I5 beyond the end I6. The wire ofthis coil is suitably covered with insulating material, such as enameland nylon. While this coil of wire is shown as being in .a centralgroove, it is obvious that it may be positioned in any one of the othergrooves, depending upon the operating characteristics desired. Also, thesize and length of the wire may be varied, to suit the need, or the wiremay be divided into a plurality of coils and connected in series or inparallel and positioned in different grooves.

Another coil of wire 2I is positioned in a groove I4, preferably nearthe base, and is made of a material that has a high temperaturecoeiicient of resistance, for a purpose to be described hereinafter.This coil is preferably made of nylon covered, enameled balco wire Niand 30% Fe) and, like the ends of the coil 20, the ends of this coilpass longitudinally through longitudinally extending grooves I5 beyondthe end I6. Also, like the coil 20, it may be divided and varied inresistance and selectively positioned in different grooves.

Electrical connector prongs 22 extend longitudinally through the bodybeyond the base I2 and slightly beyond the end I6. 'I'he portion of theprongs 22 that extend outwardly from the base l2, are adapted to bereceived by a socket member (not shown) in the control apparatus to bedescribed hereinafter. The boss I 2a spaces the base l2 from the surfaceof the socket mem- Aber to minimize heat transfer therebetween. Theportion of the prongs 22 that extend slightly beyond the end I6, but notas far beyond the end as lug I9, are each connected by soldering, orother suitable means, to one of the ends of the wires forming the coilsand 2| that the coils 2U and 2| are detachably con- It is thus seennected into a control ci-'rcui-t V through theseY prongs, which arenon-concentric'ally"spaced ito assure proper insertion in thesocketmember.'

In order to make the coils 20 and 2| less affected by drafts of airpassin'giove'r therh andv to aid in the transfer of heat uniformly from.

'the closed end of the housing is held from the ends of -the wires wdthe ends of thepro'ngs 22 by vmeans of spacing lug lI9. The housing isheld in position around the body member by '.swaging the open endthereof inwardly into the V-'shape dv groove i 3 in -the'base |-2.

With the `device completelyassembled as shown in Figures 1 and' 2,y itwill be apparent that if thecoil 2t is energized by supplying currentthereto yfrom 'asuitable velectrical source, through the'prongs-Z, heatwill begene'rated by the coil 28. Heat will then Y be transferred byAconduction through the body of thedevice to the coil 23|, by radiationand conduction through the housing 23 and -by convection through the airspace between -the housing and the body. The lag `in the heattransferwill obviously -bevdetermined by the distance of- 'coil 2| from coil 20.Also, without varying the voltage of the circuit, it 'is `possible 'tovary the wattage of the heater coil or coils and f properly positionthemAso as to vary the frequencyA of operation Without varying the totalcycling resistancedifferential or droop ofthe cycler.

Operation 'In order to more fully understand the utility on the abovedescribed cycler, its operation in a control system, such as thatshownin Figure 3 of the drawing, will now be described. A Wheatstone bridgecircuit, having apower input transformer 24, has series connectedresistance legs 25 and 26 and series connected resistance legs 2l' and28 connected across the transformer't. An amplifier is connected betweenthe junctions of legs 25 and 2G through the groundand calibratingresistors 29 and 30 to other resistors in legs-21 and 28.

The leg `25 comprises a fixed resistor 31|-, a'n

ambient temperature compensating resistor -3-2l responding to changes intemperature inthe housing of the control apparatus, a'nd a balancs'istortype of roomv limiters=36 and 3l spaced at 4 different points in theroom or house, the temperature of which is to be controlled, and partsof resistors 29 and 30. Limiter 31, the details of which form no part ofthis invention, preferably has a switch means therein for varying theresistance thereof for day and night operation.

Leg 28 has thefixed resistor 3'8v and parts of resistors 219 and 3Btherein. Y f

Legs `2'! and 28 are joined together and to the Y'ground throughresistance 29 and at a Variable point in resistance 3G. Theadjustability of the ground connection to resistance 30 properly pro--'portions` theresistances of legs 21 and 28.

'lsw-itcli,y comprising a relay coil 39 and switch armsdand-iactuatedthereby, is connected to the output s'ide'of the amplifier. A powertrans- -form'er' 42'is connected through switch arm 4|) to heater 20 ofthe cycler. The switch arm 4| is adaptediwhen closed, to complete acircuit from a suitable power means (not shown) to a fuel ifeeding means(inoty shown) through 'lead lines 43 andell- Theapparatusfis-illustrated in Figure 3 as 'being inla roomsatisedlcondition for night Aoperation. That is,.aswitch in-limiter 3-1'is opened, providing. the `greaterfresistance, so 'as torequire agreater drop-:in `ternperature in the room before unbalancing the bridgecircuit to` cause operationof'thefurnace. Under this conditionvof theapparatus, the .outdoor compensator Vtl'fmust lower iniresistance. toVbalance this increased resi'fstancelinlimiter lbefore'it canunbalance-the 'bridge to cause operation. of the fuel feeding means. I-fthe/outside temperature-remains constant, it willbe 'obviousV that thetemperature Aof the room must lower anzadditiona'l yamountl'oefore'limiter ST1 can'unbalancethe bridgeto'inie Vtiate operation.ofthe fuel feeding means.

Now assuming that the froom'thermostat is in Tits satisfied conditionand theV outside'tempera- -ture is 'suiciently 10W to have'causedthecompensator 34 'to imbalance 4the-bridgecircuitgthe amplifiercontrolledsswitch 'Willz have closed 'the circuit to the fuelY"feeding-means and thefheater 'Zit in'the'cycler. .'Ene'rgization ofthe heater 2E] willi, afterlavpredetermined time lag, heat ycoil 2| 'toincrease fitsfresistancefand. balancethe bridge `circuit. Balancing of'the bridge. circuitl Wl Vcause"d'eenergizationfof the "relayf' andopening of' the circuit to the'fheaterll and: fuelrfeeding means. Y AIfthe heat thrown'int'o-theroom during the time -'the burnersWere-'inoperationfdoes not cliangethe'resistanceiof the liiniter 36 or37, and

the "outside temperature 'hasnot: changed: during that time, the coolingoffcoil 2|. will aga-inp unbalance the bridgeA circuit to. .againenergizeA the 'heater 20 rand'. the ffluelf feeding `means; -It will"thus b'e-Vseen that theffurnace Willl periodically operate sov long .asvthere is anunbalanced condi-- 'tion diie to eitherftheroorn'temperature being belowj 'afsatisfied condition Aor ftheoutdoor At'emperature being below a predeterminedtempera- 'ture(ius'ua-lly 7.09).. Y

Theid-'uration-a'nd frequency! of operation' of :the fuel feeding meanswill obviously `.c'leperrd upon the degree ofunbalance of:thei'roomlimiters or "the fout'cioor compensator. The. greater. thefre-'duction in the resistance: inieith'er f ofl'th'e'se: con;-

trols, the longer it will be necessary forY the heater 2t to beenergizedi to increase the resist- 'ance Gif-coilZJItOftheextent:necessary toballance the bridge circuit;Infmild'we'ather;the'ifurnaice will operate for only shortperiodslofltimeiandat wideliritervals;4 il'n'lmoderateweatlier,thecycling :frequency increases andi the'4 "onA and loft tim'e periodsapproach equality at about 50% of the furnace load. The maximumfrequency of operation is also reached at this time. In Very coldWeather, the furnace will operate for much longer periods and at shorteroff-time intervals.

From the above description of the operation of the control apparatus, itWill readily be seen that in mild weather, the heating plant will supplyheat periodically at a very low temperature so as to, in effect, provideconstant heating at only a temperature necessary to maintain the desiredroom temperature. During much colder weather, the furnace will circulatea higher temperature heating medium more frequently to provide a moresteady iiow of the heating medium; while during the severest coldweather, the fuel feeding means may continuously operate due to the factthat the temperature responsive resistor 2l in the cycler cannot beheated to the extent necessary to balance the bridge circuit, theresistance of the outdoor compensator 34 having become too low. It willthus be seen that the more nearly continuous supply of heat to the roomwill be during the bitterest weather. In all conditions of operation ofthe heating apparatus, stratification of heat layers in the room orhouse will be effectively prevented due to the regularity of the supplyof the heating medium to the room.

In order to obtain the operation of the heating plant, as describedabove, it is obvious that the control apparatus must have a cyolertherein that is extremely sensitive and rugged and that will operateuniformly.

The cycler of this invention provides all of the above-mentionedcharacteristics in that the temperature sensing coil 2| is unaffected bydrafts, is mounted on a solidly constructed body and has a protectivehousing. rlhe heat from the heater 29 is carried in three ways from theheater in coil 2i, by conduction through the body of the device, byconvection air currents, and by radiation, conduction and radiationagain through the housing 23 from the coil 20 to the coil 2l. Thisassures a regular and uniform transfer of heat between said coils oneach operating cycle.

As it is apparent that modifications of the above described cycler canbe made without departing from the spirit of the invention, it is to beunderstood that the scope of the invention is to be determined solely bythe appended claims.

I claim as my invention:

1. A timing device comprising a support having a plurality of flangesdefining three or more grooves7 a heater type of electrical resistancewinding and a temperature responsive resistance control winding disposedin said grooves, one of said windings being disposed in a groove at theextreme end of said support and the other winding being disposed in oneor the other of the remaining grooves depending upon the timing perioddesired, the intermediate groove or grooves being free of windings, anda housing enclosing said support to eliminate any appreciable heattransfer effects from external air currents, the outer dimensions of theflanges between said grooves being substantially less than the internaldimensions of said housing to permit the transfer by convection of heatwithin said housing between said heater type of winding and saidtemperature responsive control winding.

2. A control device comprising a bobbin having a plurality oflongitudinally spaced peripheral grooves for selectively receiving asmaller number of coils of wire in spaced relationship, a heater coil ofwire in one of said grooves, a temperature responsive coil of Wirepositioned in a different groove from said heater coil for selectivelyvarying the timing of heat transfer from said heater coil to saidresponsive coil, a plurality of terminal prongs extending longitudinallythrough said bobbin to form connection terminals at one end thereof tobe received by a socket and to form terminals at the other end thereofto connect said heater coil and said responsive coil to said socketthrough. said prongs, and a housing spaced from the longitudinal edgeand said other end of said bobbin so that said housing will protectivelyenclose said bobbin and aid in the internal heat transfer between saidcoils by conduction, convection, and radiation.

3. An electric circuit controller comprising a support having anenlarged end and more than two longitudinally spaced peripheral groovesand a plurality of spacing lingers extending laterally andlongitudinally from the other end thereof, terminal prongs extendinglongitudinally to said support and projecting beyond the end thereof, aheater type of electrical resistor and a temperature responsiveelectrical resistor separately and selectively positioned in two of saidgrooves and connected to diiferent prongs at said other end, and acup-shaped housing spaced from and surrounding said other ends andresistances and sealingly engaging around said enlarged end so that heatmay be transferred uniformly from one of said resistances to the otherby conduction, convection and radiation without appreciable efects fromexternal air currents.

4. A control device comprising a support having a body portion and alaterally enlarged base at one end thereof and a plurality of outwardlyextending spacing fingers at the other end thereof, said body havingmore than two longitudinal- 1y spaced annular grooves, said base havinga spacer stud on its outer end and a peripheral groove therein,connector prongs extending through and outwardlyT from each end of thesupport, a heater coil encircling said body portion in one of saidgrooves, a temperature responsive coil also encircling said body portionin another of said grooves, the ends of said coils being connected todifferent ones of said prongs at said other end, and a cup-shapedhousing spaced from and enclosing said coils and body portion and havingits open end engaging the periphery of said base and bent inwardly-intosaid groove and its closed end engaging said spacing fingers.

STANLEY W. N ICKELLS.

REFERENCES CITED The following references are of record in the ille ofthis patent:

UNITED STATES PATENTS Number Name Date 1,985,691 Pugh Dec. 25, 19342,016,660 Weeks Oct. 8, 1935 2,047,796 Ogg July 14, 1936 2,355,680 RubenAug. 15, 1944 2,398,333 Shoemaker Apr. 9, 1946 2,520,509 Pfeifer et alAug. 29, 1950 FOREIGN PATENTS Number Country Date 564,541 France Jan. 4,1924

